Stripper knife



June 28, 1966 E. M. CAINE STRIPPER KNIFE Filed April 20, 1965 INVENTOR.5'0 EARLE M. CA/NE United States Patent "Ice 3,257,722 srnrrran KNIFE Myinvention is directed toward stripper knives for removing or strippingexternal insulation away from an insulated wire.

It is an object of my invention to provide a new and improved stripperknife having a thumb piece which when pressed upon by the user permitsthe user to vary in a controlled manner the amount of stripping pressureto be exerted during a stripping operation.

Another object is to provide a new and improved stripper knife of thecharacter indicated having means which, when a portion of a knife bladein the knife used for stripping is dulled, permits the blade to berepositioned in the knife in such manner as to expose :an undulledportion of the blade for further stripping operations.

Still another object of my invention is -to provide a new and improvedstripper knife of the character indicated which can be manufacturedeasily and inexpensively.

All of the foregoing and still further objects and advantages of myinvention will now be explained with reference both to thisspecification and to the drawings wherein:

FIG. 1 is a side view of my stripper knife;

1 FIG. 2 is a side view of a knife blade used in my knife;

FIG. 3 is a top view of my knife;

FIG. 4 is a cross sectional view taken along 4-4 in FIG. 1;

FIG. 5 is an enlarged detail view of the horizontal slot and bladepositioning means as employed in my knife; and

FIG. 6 is a detail view of a spring element utilized in the bladepositioning means in my knife.

Referring now to FIGS. 16, there is shown a pair of elongatedhorizontally extending parallel plates 10 and 12 connected togetherintegrally at their bottom horizontal edges by a horizontally extendingcurved member 14 whereby a space 16 is defined between plates 10 and 12.Plates l0 and 12 are provided with a plurality of transverse sets ofaligned circular holes 18, 20 and 22 which are horizontally spaced apart:and are of different diameters to accommodate insulated wires ofdifferent diameters. The aligned top horizontal edges of these platescarry aligned notches 24-.

Each of plates 1t) and 12 adjacent one end (the left hand end as shownin the drawings) is provided with an elongated horizontal slot 26 havingalong its periphery a plurality of horizontally spaced verticallyextending slits 28. The slots and slits of both plates :are aligned witheach other.

I further provide a horizontally extending knife blade 30 having abottom horizontal cutting edge 32 and a top horizontal edge 34- withadjacent side horizontal grooves 36. Grooves 36 are slidably engaged by:a thumb piece 38 riding on top of edge 34 in notches 24.

The left hand end of blade 30 terminates in a shank portion 40 having ahole 42 therein. A bushing 44 extends through this hole and the alignedslots 26 whereby the blade is held in space 16 between plates 10 and 12.Extending within bushing 44 is a spring element 56 having first :andsecond sets of aligned ends 48 and 5t).

When the ends in either of sets 48 or 569 are squeezed manually towardeach other, these ends are movable in 3,257,722 Patented June 23, 1%66slots 26 whereby the blade can be moved back and forth horizontallybetween plates ll) and 12. When the pressure on these ends is released,these ends will fit into one or another of slits 28 to lock the blade inposition.

Thus, when stripping operations are carried out and the portion of thecutting edge communicating with the sets of aligned holes are dulled byrepeated use, the blade can be moved back or forth by operation of thespring element to expose a fresh portion of the cutting edge to the setsof aligned holes, thus permitting my knife to be used for a much largernumber of stripping operations than heretofore available. Moreover, bysliding thumb piece to a position just above the particular set ofaligned holes to be used for a stripping operation, thumb pressure onthis piece can control the stripping pressure to be used. Of course,when this pressure is exerted, the cutting edge of the blade is moveddownward into the aligned holes.

While I have described my invention with particular reference to thedrawings, my protection is to be limited only by the terms of the claimswhich follow.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. A stripper knife for stripping insulation away from an insulatedwire, said knife comprising first and. second horizontal plates securedto each other in spaced apart relation to define a space therebetween,an elongated horizontal knife blade disposed in said space and having abottom horizontal cutting edge, each plate, adjacent one end thereof,having a horizontal elongated slot, the horizontal slots being aligned,means connected to said blade adjacent one end thereof and riding in thealigned slots, said means when manually actuated moving said bladehorizontally back and forth to a selected position in said space, saidplates being provided with a plurality of sets of transverse alignedround holes, the various sets of aligned holes being horizontally spacedapart from each other, and a thumb piece secured to the top horizontaledge of the blade which when pressed down against the blade causes thebottom edge thereof to penetrate into the sets of aligned holes.

2. A stripper knife as set forth in claim 1 wherein said piece isslidable along the top edge of the blade.

3. A stripper knife as set forth in claim 2 wherein said sets of holesvary in diameter.

4. A stripper knife as set forth in claim 3 wherein the periphery of thealigned slots carries a plurality of vertical slits horizontally spacedapart from each other, and said means is provided with a spring elementwhich can be selectively placed in any one of the slits whereby theposition of the blade in said space is determined accordingly.

5. A stripper blade as set forth in claim 4 wherein said plates areprovided with aligned notches in the top horizontal edges thereof, saidthumb piece being slidable along the top edge of the blade within thealigned notches.

References Cited by the Examiner UNITED STATES PATENTS 2,133,005 10/1938Wollenweber s1 9.5

2,187,215 1/1940 Spinello 30 91 2,662,283 12/1953 Gienger 30 913,192,624 7/1965 Gringer s0 293 X FOREIGN PATENTS 1,050,414 2/1959Germany.

WlLLIAM FELDMAN, Primary Examiner.

MYRON C. KRUSE, Examiner.

1. A STRIPPER KNIFE FOR STRIPPING INSULATION AWAY FROM AN INSULATEDWIRE, SAID KNIFE COMPRISING FIRST AND SECOND HORIZONTAL PLATES SECUREDTO EACH OTHER IN SPACED APART RELATION TO DEFINE A SPACED THEREBETWEEN,AN ELONGATED HORIZONTAL KNIFE BLADE DISPOSED IN SAID SPACE AND HAVING ABOTTOM HORIZONTAL CUTTING EDGE, EACH PLATE, ADJACENT ONE END THEREOF,HAVING A HORIZONTAL ELONGATED SLOT, THE HORIZONTAL SLOTS BEING ALIGNED,MEANS CONNECTED TO SAID BLADE ADJACENT ONE END THEREOF, AND RIDING INTHE ALIGNED SLOTS, SAID MEANS WHEN MANUALLY ACTUATED MOVING SAID BLADEHORIZONTALLY BACK AND FORTH TO A SELECTED POSITION IN SAID SPACE, SAIDPLATES BEING PROVIDED WITH A PLURALITY OF SETS OF TRANSVERSE ALIGNEDROUND HOLES, THE VARIOUS SETS OF ALIGNED HOLES BEING HORIZONTALLY SPACEDAPART FROM EACH OTHER, AND A THUMB PIECE SECURED TO THE TOP HORIZONTALBLADE CAUSES THE BOTTOM EDGE THEREOF TO PENETRAE INTO THE SETS OFALIGNED HOLES.